xpathSupport = (XPathContext) doc.getUserData(XPATH_CONTEXT);
if (xpathSupport == null) {
JAXPExtensionsProvider jep = getProviderInstance();
xpathSupport = new XPathContext(jep);
xpathSupport.setVarStack(new JAXPVariableStack(variableResolver));
doc.setUserData(XPATH_CONTEXT, xpathSupport, null);
}
context = node;
nsContext = NokogiriNamespaceContext.create();